In the past I learned from my christian friends that a good deed disclosed is a wasted deed in the eyes of God. That a good deed should be done and never spoken of. This is a fairly widely held belief in my area of the world.
I now understand the reasoning behind this belief. The doing of the good deed is not for the purpose of bragging. The fear is that incentivizing this disclosure leads to an expectation of praise as the sole purpose behind doing good deeds. It becomes a trade of sorts rather than a wholesome deed and loses some merit as result of desire for praise as payment.
However keeping good deeds to oneself reduces the number of good deeds witnessed by others. Good deeds witnessed by others inspire others to carry out good deeds. It amplifies good deeds and proliferates the idea of doing good deeds. More people do good deeds as a result. I've experienced this just recently with the sharing of picking up trash while hiking.
Knowledge and expression of good deeds should be shared as it amplifies the reach of the good deed. If the concern is bragging and desire for praise, simply check the intentions of the expression for this desire and remove it to the best of ability before expressing the good deed to others.